Lens grinding and polishing machine



June 23, 1931. l. G. VETTER LENS GRINDING AND POLISHING MACHINE Filed June 25, 1927 9 WNTOR.

M ATTORNEY.

Patented June 23, 1931 T UNITED STATES PATENT OFFICE IGNATZ G. VETTER, or BUFFALO, New YORK i LENS GRINDING AND POLISHING- MAGHINE 7 Application filed June 25,

My invention has reference to a lens 1 grinding and polishing machine, and pertains more specially to that type of such machines which is set forth in Letters Pat- 5 ent of the United States No. 1,588,435,

issued to Charles A. Adams June 15, 1926.

'This machine makes use of a spherical or face of the ball will be inturn brought into contact with the operating faces of the tools. In practice it has been discovered that the lower tool has a dominant effect upon the blocker, causing it to spin constantly in the direction in which the tool is moving. Certa-in lenses were thereby caused to rotate continuously along the line of the space between the two tools, without receiving any benefit therefrom.

To remedy this defect it was undertaken providing a brake device therefor. This was in part satisfactory, but was still ineffective, for the reason that the frictional force of the brake had to be adjusted to conform to the frictional-action between the tools and blocker, and as this frictional action is constantly changing, the brake mechanism did not work successfully. In the operation of a machine of the type named it is usual to supply the grinding material with which the tools are provided with water, and immediately after being thus supplied the friction between the blocker and tools is much less than after-the tools have operated for a time, and the moisture been dissipated by the action of the tools. As this occurs the friction increases, and there is a constantly growing tendency of the blocker to rotate with the lower tool. As a result if the brake mechanism is provided with a tension which will conform to tool support in detail. r

and connections thereof. to retard the movement of the blocker, by

1927. Serial No. 201,354.

the looser operation of the blocker, itwill become useless as the friction on the blocker increases, and if, on the other hand, the brake is set to conform tothe operation of the machine when the grinding material is dried out, it will fail to act when the material is supplied with more moisture.

The chief purpose of the present invention is to provide the lower tool with an eccentric movement, which, in connection with a'suitable brake or control mechanism for the blocker, will produce the desired result, and impart a satisfactory movement to the blocker at all times.

The above named, and other purposes and advantages of the invention, will be more fully apprehended from the following specification, due reference being had to the accompanying drawings, in which Fig. 1 shows a fragmentary portion of a machine embodying the invention, in side elevation. I

Fig. 2 is a plan view of the lower tool, with the superstructure broken away.

Fig.3 is a vertical section of the lower Fig. 4 is a sectional detail of the tool 15 The'reference number l indicates the upper part of a frame, from which extends a support 2, in the end of which is rotatably mounted a vertical shaft 3, provided with a pulley 4, by means of which the shaft may be given rotation, as by a belt .5. On the upper end of the shaft 3 is mounted a bowlshaped tool 6, by means of a stem 7 on the tool fixed in the upper end of an arbor 8, which is inrturn fixed on the upper end of the shaft 3, in such a manner that the center line of the arbor willbe out of line with the axial line of said shaft.- As a result the rotary movement of the shaft 3 will be imparted to the arbor 8 and tool 6 to give a limited orbital movement thereto, for the purpose hereinafter pointed out. 1

Atthe upper end of the frame 1' is an arm 9, in line with the support 2,'inthe end of which arm is'rotatably mounted a shaft 10, fitted with a pulley 11, so that the shaft may be driven by a belt'12. 011 the lower end of the shaft 10 is fixed a disk 13, with a central pin 14 for engagement with an upper tool 15, adapted to operate in opposition to the tool 6. The disk 13 is also provided with a pin 16 for engagement with an opening in the tool 15, to compel the rotation thereof with the shaft 10, the connection of the pin 14 with said tool being of such a character as to permit a slight rocking movement of the tool during the rotation thereof.

Between the tools 15 and 6 is held a spherical blocker 17, capable of containing on its surface a plurality of lenses for grinding or polishing, as shown at 18. The downward pressure of the tool 15 is suflicient to lend the necessary amount of frictional action to the tool 6, and also to the tool 15, to have the desired operation on the lenses, and this pressure maybe increased if desired by means of a weight on the upper end of the shaft 10. In the operation of the machine the shaft driving mechanism is geared so as to cause a rotation of the shafts 3 and 10 in opposite directions.

Projecting from the frame 1 at the side of the tool 6 is a bracket 19, in which is rockingly mounted a shaft 20, fixed to one end of which is a support 21. Projected from said support is a rod 22, on the end of which is a brake 23, fitted with a shoe 24; of felt or other material, adapted for engagement with the face of the blocker 17, and conforming to the shape thereof. The other end of the shaft 20 is bent forwardly into an arm 25, upon which are slidably mounted .weights 26 and 27, with means for holding the same in stationary position thereon. By this means the brake is held in yieldable contact with the face of the blocker.

In the operation of the machine the tool 6 in its orbital movement carries with it the blocker 17, the brake 23 moving back and forth in response to the movement of the blocker, and being at all times in close contact therewith. The degree of pressure of the brake can be regulated by shifting the positions of the weights on the arm 25, no change having to be made therein after the operation begins. The effect of the com- 1 bined orbital movement of the tool 6 and pressure of the brake on the blocker is to cause a constant shifting of the position of the blocker, bringing new lenses into operative positions in succession. In the movement of the tool and blocker the upper tool 15 is permitted a rocking rotary movement, conforming to the orbital movement of the blocker. The general effect is to-make a successful operation out of what has heretofore been an unsuccessful one.

What I claim, and desire to secure by Letters Patent, is:

1. In a device of the classdescribed, a frame and tool support mounted therein so as to be capable of an orbital movement, a

lens grinding tool fixed on said support, adapted to hold a spherical blocker for grinding, an auxiliary grinding tool mounted above said blocker for operation in opposition thereto, a support rockingly mounted in proximity to said first-named tool, and pressure device carried thereby, and means for holding said last-named support with said pressure device yieldably in position to exert pressure against a blocker held in said tools.

2. In a device of the class described, a frame and pair of supports projected therefrom, in a vertical plane, a shaft rotatably mounted in one of said supports, a grinding tool mounted on said shaft so as to be given an orbital movement upon the operation thereof, a shaft in the other support, and a grinding tool carried thereby in opposition to said first-named grinding tool, means for operating said last-named shaft in a direction contrary to that of the first named shaft, a pressure device vadapted for engagement with the face of a blocker contained in said first-named grinding tool,

frame and tool support mounted therein so:-

as to be capable of a rotary movement, a lens grinding tool fixed on said support, adapted to hold a spherical blocker for grinding, an auxiliary grindingtool mounted above said blocked for operation in op position thereto, a support rockingly mounted in proxlmity to sald first-named tool, a pressure device carried thereby, and means for holding said last-named support with said pressure device yieldably in positlon toaz exert pressure against a blocker held in said tools. 7

In testimony whereof I affiX my signature.

IGNATZ G. VETTER. 

